
<template>
  <div class="app-container">
    <h2 style="text-align: center;">发布新课程</h2>

    <el-steps :active="1" process-status="wait" align-center style="margin-bottom: 40px;">
      <el-step title="填写课程基本信息"/>
      <el-step title="创建课程大纲"/>
      <el-step title="最终发布"/>
    </el-steps>

    <el-form label-width="120px">
     
    <el-form-item label="课程标题">
        <el-input v-model="courseInfo.title" placeholder=" 示例：机器学习项目课：从基础到搭建项目视频课程。专业名称注意大小写"/>
    </el-form-item>

    <!-- 所属分类 TODO -->
    <el-form-item label="课程分类">
    <!-- 一级分类 -->
    <el-select
        v-model="courseInfo.subjectParentId"
        placeholder="请选择一级分类" @change="subjectLevelOneChanged">
        <el-option
            v-for="subject in subjectOneList"
            :key="subject.id"
            :label="subject.title"
            :value="subject.id"/>
    </el-select>

    <!-- 二级分类 -->
    <el-select v-model="courseInfo.subjectId" placeholder="请选择">
        <el-option
            v-for="subject in subjectTwoList"
            :key="subject.id"
            :label="subject.title"
            :value="subject.id"/>
    </el-select>
    </el-form-item>

    <!-- 课程讲师 -->
    <el-form-item label="课程讲师">
    <el-select
        v-model="courseInfo.teacherId"
        placeholder="请选择讲师">
        <el-option
            v-for="teacher in teacherList"
            :key="teacher.id"
            :label="teacher.name"
            :value="teacher.id"/>
    </el-select>
    </el-form-item>

    <el-form-item label="总课时">
        <el-input-number :min="0" v-model="courseInfo.lessonNum" controls-position="right" placeholder="请填写课程的总课时数"/>
    </el-form-item>
    <!-- 课程简介-->
    <el-form-item label="课程简介">
         <tinymce :height="300" v-model="courseInfo.description"/>
    </el-form-item>

    <!-- 课程封面 -->
    <el-form-item label="课程封面">
    <el-upload
        :show-file-list="false"
        :on-success="handleAvatarSuccess"
        :before-upload="beforeAvatarUpload"
        :action="BASE_API+'/eduoss/fileOss'"
        class="avatar-uploader">
        <img :src="courseInfo.cover">
    </el-upload>
    </el-form-item>

    <el-form-item label="课程价格">
        <el-input-number :min="0" v-model="courseInfo.price" controls-position="right" placeholder="免费课程请设置为0元"/> 元
    </el-form-item>
    <el-form-item>
        <el-button :disabled="saveBtnDisabled" type="primary" @click="saveOrUpdate">保存并下一步</el-button>
    </el-form-item>
    </el-form>
  </div>
</template>

<script>

import course from '@/api/edu/course'
import subject from '@/api/edu/subject'
import Tinymce from '@/components/Tinymce'

export default {
    components: { Tinymce },
    data() {
        return {
            saveBtnDisabled: false,
            courseInfo: {
                 title: '',
                 subjectId: '', //二级分类Id
                 subjectParentId: '', //一级分类Id
                 teacherId: '',
                 lessonNum: 0,
                 description: '',
                 cover: '',
                 price: 0
            },
            BASE_API: process.env.BASE_API, // 接口API地址
            teacherList: [], //存放所有讲师的数据
            subjectOneList: [], //一级分类
            subjectTwoList: [], //二级分类
            courseId: ''
        }
    },
    created() {
       this.init()
    },
     watch: {
      //监听路由变化
      $route(to, from) {
        this.init()
        this.courseInfo = {}
      }
    },
    methods: {
        //页面初始化方法
        init() {
            if(this.$route.params && this.$route.params.id) {
                this.courseId = this.$route.params.id
                this.getInfo()
            }else{
                this.getListTeacher()
                this.getOneSubject()
                this.courseInfo.cover = '/static/1.jpg'
            }
        },
        //根据课程id查询
        getInfo() {
            course.getCourseInfoId(this.courseId)
                    .then(response => {      
                        this.courseInfo = response.data.courseInfoVo         
                        //查询有的分类
                        subject.getSubjectList()
                               .then(res => {
                                   //获取所有一级分类
                                   this.subjectOneList= res.data.list
                                   //把所有一级分类数组进行遍历,比较当前curseInfo里面一级分类id和所有一级分类id
                                   for (var i = 0; i < this.subjectOneList.length; i++) {
                                       var oneSubject = this.subjectOneList[i]
                                       if(this.courseInfo.subjectParentId === oneSubject.id) {
                                           this.subjectTwoList = oneSubject.children
                                       }
                                   }
                               })
                               this.getListTeacher()
                    })
        },
        //上传封面之前
        beforeAvatarUpload(file) {
            const isJPG = file.type === 'image/jpeg'
            const isLt2M = file.size / 1024 / 1024 < 2
            if (!isJPG) {
                this.$message.error('上传头像图片只能是 JPG 格式!')
            }
            if (!isLt2M) {
                this.$message.error('上传头像图片大小不能超过 2MB!')
            }
            return isJPG && isLt2M
        },
        //上传封面成功
        handleAvatarSuccess(res,file) {
            this.courseInfo.cover = res.data.url
        },
        //当一级分类发生改变执行得方法 value就是一级分类id值
        subjectLevelOneChanged(value) {
            for (var i = 0;i < this.subjectOneList.length;i++) {
                var oneSubject = this.subjectOneList[i]
                if(value === oneSubject.id) {
                    this.subjectTwoList = oneSubject.children
                    this.courseInfo.subjectId = ''
                }
            }
        },
        //查询所有的一级分类
        getOneSubject() {
            subject.getSubjectList().then(response => {this.subjectOneList = response.data.list})
        },
        //查询所有的讲师
        getListTeacher() {
            course.getListTeacher().then(response => {this.teacherList = response.data.items})
        },
        //添加方法
        addCourse() {
            course.addCourseInfo(this.courseInfo).then(response => {
                  this.$message({
                         type: 'success',
                         message: '添加课程信息成功!'
                       })
                this.$router.push({path:'/edu/course/chapter/'+response.data.courseId})
            })
        },
        //修改方法
        updateCourse() {
            course.updateCourseInfo(this.courseInfo)
                  .then(response => {
                      this.$message({
                         type: 'success',
                         message: '修改课程信息成功!'
                       })
                    this.$router.push({path:'/edu/course/chapter/'+this.courseId})
                  })
        },
        //调用添加或修改
        saveOrUpdate() {
           if(this.courseInfo.id) {
               this.updateCourse()
           }else{
               this.addCourse()
           }
           
        }
    }
}
</script>

<style scoped>
.tinymce-container {
  line-height: 29px;
}
</style>